Spinal mobility has for a long time been determined using manual methods, where the practitioner would press down on one or more vertebra to be analyzed. Such methods are subjective, as the practitioner would try to move the vertebra to be tested with his/her fingers or hand and make an observation based on how much mobility he/she could detect. The practitioner would than make a record of his observation, which is not referenced to any standard, and comparison over a period of time would be very difficult and inaccurate.
Devices have been suggested in order to measure spinal mobility objectively. U.S. Pat. No. 6,539,328 discloses a device comprising an impulse and sensing head, which determines spinal segment mobility by applying a force impulse at an angle of incidence to a spinal segment and generating a wave form characteristic of spinal mobility. An inclinometer determines the angle of incidence of contact with the spinal segment in one or more axis. The device collects data signals from the inclinometer and the head in such a manner that a signal corresponding to the angle of incidence at the same time will be captured by the data acquisition circuitry. This patent document also describes earlier prior art devices based on piezoelectric sensors and measurements of electronic waveforms reflecting the resistance of a spinal segment under pressure. These devices have however not been used commercially and there is a clear need for alternative, simple and accurate devices for measuring spinal mobility.